Childproof closure

ABSTRACT

The Specification discloses a childproof screw closure for a container, comprising an inner closure member and an outer closure member which shrouds the inner closure member and is held captive on the same. The outer closure member is axially movable on the inner closure member and has projections arranged so that when the outer closure member is axially depressed against a bias, they engage projections on the inner closure member and thereby enable the closure to be unscrewed. To enable the closure to be screwed up irrespective of the relative axial positions of the inner and outer closure members, the skirt of the outer closure member is formed with ratchets which are biassed resiliently against knurls formed on the periphery of the skirt of the inner closure member. Preferably the skirt of the outer closure member is locally reduced in thickness on either side of each ratchet so as to provide the desired characteristics for the ratchets.

Rayner et a1.

Oct. 14, 1975 CHILDPROOF CLOSURE Inventors: Adrien Patrick Rayner,Huntsmoor Lodge, Iver, Buckinghamshire; Christopher James Niebuhr Tod, 2Maudlyn House, Steyning, Sussex; Michael James, 11 Connaught Ave.,Shoreham-By-Sea, Sussex, all of England Filed: Sept. 23, 1974 Appl. No.:508,566

Foreign Application Priority Data Mar. 22, 1974 United Kingdom 12957/74June 28, 1974 United Kingdom 28709/74 us. C1. 215/220; 215/9 rm. c1.B65D 55/02 Field of Search 215/9, 219, 220

References Cited UNITED STATES PATENTS Primary ExaminerGeorge T. HallAttorney, Agent, or FirmKenyon & Kenyon Reilly Carr & Chapin [5 7]ABSTRACT The Specification discloses a childproof screw closure I for acontainer, comprising an inner closure member and an outer closuremember which shrouds the inner closure member and is held captive on thesame. The outer closure member is axially movable on the inner closuremember and has projections arranged so that when the outer closuremember is axially depressed against a bias, they engage projections onthe inner closure member and thereby enable the closure to be unscrewed.To enable the closure to be screwed up irrespective of the relativeaxial positions of the inner and outer closure members, the skirt of theouter closure member is formed with ratchets which are biassedresiliently against knurls formed on the periphcry of the skirt of theinner closure member. Preferably the skirt of the outer closure memberis locally reduced in thickness on either side of each ratchet so as toprovide the desired characteristics for the ratchets.

lb 7) H US. Patent Oct. 14, 1975 Sheet 3 of3 3,912,101

CHILDPROOF CLOSURE This invention relates to closures of the type whichare normally known as childproof closures and which are hereinafter tobe referred to by that name. By a childproof closure is meant a closurewhich is designed to prevent a child from gaining access to thepotentially harmful contents of a bottle or the like which is closed bythe closure.

According to the present invention from one aspect there is provided achildproof closure comprising an inner closure member having a crown anda depending skirt with cam formations for cooperation with complementarycam formations on a container to be closed, and a plastics outer closuremember shrouding the inner closure member and having a crown to overlieat least part of the crown of the inner closure member and a skirt tooverlie the first said skirt, the outer closure member being captive onthe inner closure member and being at least in part axially moveable onthe inner closure member and biassed to a position in which the outerclosure member is freely rotatable on the inner closure member in thesense to disengage the closure from the said container, there beingprovided means on the inner and outer closure members which are mutuallyengageable on depression of the outer closure member or the said partthereof against the bias to provide a positive drive between the closuremembers enabling disengagement of the closure from the container, aplurality of projections formed on the outer periphery of the innerclosure member skirt and a plurality of ratchets in the form of thintongues of plastics material which project integrally and inwardly fromthe outer closure member skirt into engagement with the inner closuremember skirt and which are engageable behind the said projections so asat all times to enable a positive drive to be effected between themembers, in the sense to engage the closure on the container andirrespective of the axial position of the outer closure member on theinner closure member, each ratchet being arranged so as to rideresiliently over the said projections when the outer closure member isturned in the sense to disengage the closure from the container.

Preferably each ratchet is integrally rooted on the plastics material ofthe outer closure member skirt, which is locally reduced in thicknessadjacent the ratchet root on at least one side thereof.

In accordance with the invention from a second aspect there is provideda said outer closure member for a closure as defined above.

In order that the invention may be more fully understood severalembodiments thereof will now be described, by way of example, withreference to the accompanying drawings, in which:

FIG. 1 is a diagrammatic section on a diametral plane of a closure inaccordance with the invention when in position on a bottle for medicinalpills;

FIG. 2 is a diagrammatic view showing the outer closure member formingpart of the clsoure of FIG. 1 when free of the inner closure memberforming the other closure part and at two different vertical sections,the part to the right of the central axis XX being taken on the linellA-llA of FIG. 3 and the part to the left of that axis being taken onthe line llBllB of that figure;

FIG. 3 is a quadrant of the outer closure member as seen on thehorizontal section represented by the line III-III of FIG. 2;

FIG. 4 is a view corresponding to FIG. 2 of another outer closure memberin accordance with the invention;

FIG. 5 is a top view, partly broken away, of the outer closure member ofFIG. 4; and

FIG. 6 is a section, to an enlarged scale, of a part of FIG. 5.

Throughout the drawings, the same reference numerals are used toindicate like or analogous parts.

Referring now to FIGS. 1 to 3, a closure for the screw-threaded neck 9(FIG. 1) of a glass bottle for medicinal pills is formed of an innerclosure member 1 and an outer closure member 2 which is fitted onto theinner closure member and is held captive thereon as is to be described.

The inner closure member is conventional. It is integrally moulded inone piece from high density polyethylene and comprises a generally planecrown 3 and a depending generally cylindrical skirt 4 both of which areessentially rigid. The skirt 4 is internally formed with screw threads 7to engage the screw-threads 8 of the bottle finish. Externally the skirtis regularly formed with vertical knurls 10 separated by grooves 43; oneeach of the knurls and of the grooves is respectively visible in fulllines to the right and left of the inner closure member as seen inFIG. 1. At their bottom ends the knurls merge with an outwardlyprojecting bead 24 formed circumferentially around the bottom free edgeof the skirt exterior.

The crown 3 is integrally formed at its underside with a dependantannular ring 18 which resiliently engages the annular top surface 17 ofthe bottle finish so as to prevent contamination of the bottle contentsby moisture etc., whilst also providing frictional resistance torotation of the closure cap on the bottle for the purpose later tobecome apparent. The ring 18 is of thin material; it is angled inwardlyof the cap in the direction towards its free edge, so that, as isapparent from FIG. 1, it is deformed upwardly by its engagement with thebottle when the closure is screwed home.

Externally the crown 3 is formed with radial continuations of the knurls10 and the grooves 43. The crests of the knurl continuations form partof the top surface 23 of the crown; the groove continuations decreaseprogressively in depth in the direction towards the centre of the crownso that the knurls terminate at a circular locus 25 centred on thecentral axis XX of the closure. In a modification the continuations ofthe knurls and grooves have a component of direction circumferentiallyof the cap.

The outer closure member 2 is integrally moulded in one piece from highdensity polyethylene and comprises a crown 5 and a dependant skirt whichoverlie, respectively, the crown 3 and skirt 4 of the inner closuremember 1.

The outer closure member is held captive on the closure cap byengagement of a bead 13 under the bead 24 of the inner closure member.The bead 13 is formed continuously around the skirt 6 inner periphery,adjacent the free bottom edge of the outer closure member.

The crown 5 of the outer closure member has a thickness which issubstantially smaller than that of the skirt 6. Whereas the skirt 6 hassubstantial rigidity, the crown 5 is readily deformable axially of theclosure.

The crown is chamfered at 35 around its periphery; at its centre itcarries a boss 29 in the form of an openbottomed cylinder which dependsfrom the underside of the crown 5 at its top end and which at its bottomend engages the top surface 23 of the inner closure member at a circularfree edge 41. The relative dimensions of the inner and outer closuremembers are chosen so that when as shown in FIG. 1, the outer closuremember is held captive on the inner closure member by engagement of thebeads 13 and 24, the crown 5 is upwardly and resiliently deformed byupward pressure exerted by the boss 29 in cooperation with the crown 3;this deformation, however, is insufficient to completely remove theconcavity with which the crown 5 is formed during moulding (FIG. 2).

It will therefore be appreciated that by virtue of its own arrangementand its engagement with the inner closure member, the outer closuremember 2 is held captive on the inner closure member 1 in a positivemanner which allows a user to depress the skirt 6 of the outer closuremember axially in relation to the skirt 4 of the inner closure member bypressing on the annular portion 16 of the crown 5 lying radially outsidethe boss 29. The purpose of this movement will later become apparent.

Referring now to FIGS. 2 and 3 in particular, in addition to thecontinuous bead 13 the skirt 6 of the outer closure member is internallyformed with alternate lugs 11 and ratchets 19 of which nine of each areprovided. The lugs are rigid and regularly disposed around the skirt 6at a 40 pitch. The ratchets are flexible (as is later to be described);like the lugs, they have a 40 relative pitch.

The lugs 11 are vertical and carried on respective bearing lands 33which are generally rectangular and project inwardly from the base innersurface 34 of the skirt 6. The lands merge with the underside of thechamfer 35 at their top ends; from there they extend verticallydownwardly by approximately two-thirds of the skirt length. The landsare of such a thickness that, as can be seen at the right hand side ofFIG. 1, they engage the crests of the knurls forming part of thegenerally cylindrical outside surface of the skirt; they thereby at alltimes maintain satisfactory axial alignment of the outer closure memberon the inner closure member.

The lugs 11 are relatively short in length. They merge with the chamfer35 at their top ends and there from extend downwardly for a distancewhich is slightly shorter than the spacing of the crowns 3,5 when theouter closure member is in its relaxed (but captive) condition as shownin FIG. 1.

The ratchets 19 are thin vertical pieces of plastics material which areof constant thickness and are coextensive in the vertical sense with thelands 33; they are joined to the undersurface of the chamfer 35 at theirtop ends. Along their outer edges the ratchets are rooted at the baseinner surface 34 of the skirt 6 so as to be inherently biassed away fromthe surface 34 and into contact with the skirt 4 of the inner closuremember.

The outer surface 36 of the skirt 6 is generally cylindrical but isformed at regular intervals with nine isosceles-triangular depressions37 each of which extends up the skirt 6 with its apex in radial andlongitudinal correspondance with the root of a respective ratchet 19. Ascan particularly be seen from FIG. 3, each depression provides reducedthickness neck portions adjacent the root of its associated ratchet 19on either side thereof. As will later become apparent, these neckportions form integral hinges for the ratchets.

To assemble the closure intitally the outer closure member 2 is pressedaxially over the inner closure member 1 until its bead 13 rides over thebead 24 and thereafter snaps resiliently underneath that bead to holdthe outer closure member captive on the inner closure member asdescribed above.

To screw the assembled closure onto a medicinal bottle it is then merelyrequired to rotate the outer closure member in the normal clockwisedirection. As can be seen from FIG. 3, each ratchet 19 is inclined inrelation to the cap radius through its root. The sense of thisinclination is such that the clockwise rotation of the outer closuremember drives the ratchets into engagement behind knurls 10 of the innerclosure member skirt 4 at the radially extending free edges 38 of theratchets. It will accordingly be seen that the ratchets l9 enable apositive connection to be effected between the members 1,2 so as toenable the closure to be screwed up in the normal manner irrespective ofthe axial position of the outer closure member on the inner closuremember.

If, however, an attempt is made to undo the closure by merely turningthe outer closure member in the normal anticlockwise direction, theratchets 19 ride over the knurls 10 so allow free relative rotationbetween the closure members; the outer closure member is thereforeturned without effecting any rotation of the closure. It will beappreciated that for this to occur the previously described frictionalresistance between the ring 18 (FIG. 1) and the top surface 17 of thebottle finish must be sufficient to withstand the torque frictionallygenerated by the ratchets as they move over the knurls.

In order to undo the closure it is necessary first to axially depressthe portion 16 of the outer closure member 2 as previously described,sufficiently to move the lugs 11 into the top ends of grooves 43 on theskirt 4. The positive drive thereby effected between the two membersthen enables simultaneous rotation of the outer closure member in theanticlockwise direction to unscrew the closure and so gain access to thecontents of the bottle.

During the riding movement of the ratchets 19 over the outer surface ofthe skirt 4 as described in the penultimate paragraph, the neck portions40 provided by the depressions 37 act as integral hinges allowing theratchets 19 to rock on their roots. In conjunction with a small andinconsequential degree of flexing of the ratchets themselves thisrotation accommodates the reciprocating radial movements of the ratchettips as they pass alternatively over the knurls 10 and grooves 43 of the.skirt 4.

In this respect it will be noted that the ratchets are thicker than theyotherwise could satisfactorily be from the point of view of theirability to flex in the absence of the depressions 37. The thickness and,therefore, the rigidity of the ratchets is, in fact, chosen to satisfythe function of the ratchets to provide the positive drive required, aspreviously described, to screw the closure onto the bottle. Theprovision of the neck portions 40 by means of the depressions 37therefore reconciles the conflicting requirements for the ratchets to beof high rigidity when required to provide positive drive for screwingup, but to be highly flexible when required to ride over the knurls toprevent unathorised unscrewing.

In the embodiment of FIGS. 4 to 6 the ratchets 19 are in a modified formto that of the ratchets of FIGS. 1 to 3. In contrast with the firstembodiment the skirt 6 of the outer closure member 2 is not locallyreduced in thickness on either side of each of the ratchets; instead,the necessary characteristics of resilience and capability to deform areprovided in the ratchets themselves. In FIGS. 4 to 6 each ratchet 19comprises a root portion 20 outstanding orthogonally from the skirtwall, and a thicker and essentially rigid inner closure member engagingportion 21 which is inclined in the appropriate direction, that is tosay, in the clockwise sense required for the ratchet to engage theknurls 10 for screwing-up the closure. The thickness of theroot portions20 is suitably chosen to give the required characteristics for theratchet operation.

A further way in which the second embodiment differs from that of FIGS.1 to 3 is that the boss 29 is closed at its bottom rather than its topend. It therefore forms a well 42 having a bottom 12 engaging the crown3 of the inner closure member 1, and side walls 15 which are slightlyconvergent towards the bottom 12.

In a modification of the arrangement of FIGS. 1 to 3, a well such as isshown at 12 in FIGS. 4 to 6 replaces the boss 29; correspondingly, aboss such as is shown at 29 can replace the well 12 in the arrangementsof FIGS. 4 to 6.

In further modifications of the described embodiments: the integralsealing ring 18 is replaced by a separate wad of suitable material; thecrown 5 of the outer closure member is made plane and essentially rigidand the boss 29 or well 42 is replaced by integral spring fingers on thecrown 3 and/or 5 by a spring or springs separately provided; and thelugs 11 are omitted and replaced by formations on the underside of thecrown 5 which are arranged for engagement with the knurl continuationsat the top of the crown 3 or with other formations specially provided.

Although in the embodiment described with reference to FIGS. 1 to 3 thedepressions 37 are shown and described as isosceles triangular andcentred symmetrically on the root of the associated ratchet 19, for someapplications it may be found desirable to make the depressions of adifferent crosssectional shape and/or to make them assymmetrical withrespect to the ratchet roots.

In a further possible modification of the first embodiment grooves orslots, preferably part-cylindrical, are formed in the interior surface34 of the skirt 6 immediately adjacent the roots of the ratchets 19 soas locally to reduce the skirt thickness and form a residual hinge forthe ratchet. Only one such groove or slot may be provided for eachratchet; alternatively two grooves or slots may be provided, one on eachside of the ratchet root. With the provision of these grooves or slotsthe depressions 37 may be omitted if desired.

Although the invention has been described in relation to an innerclosure member of plastics material, the inner closure member of aclosure in accordance with the invention may be of metal.

The invention is in no way limited in application to glass bottles formedicinal pills as particularly described; it may be used in relation toother types of container (which may be of glass, plastics and/or metal),

and for other types of product, sealed or otherwise, which are dangerousto a child.

In the latter respect it will be noted that in each of the describedembodiments the outer .closure member completely shrouds the innerclosure member so that access to the bottle contents can only beachieved through the agency of the lugs 11. The simultaneous depressionand rotation of the outer closure member necessary to achieve unscrewingis not within the capabilities of a child, so that only an adult whoknows the required combination of movements can gain access to thebottle contents.

What we claim is:

l. A childproof closure, comprising an inner closure member having acrown and a depending skirt with cam formations for cooperation withcomplementary cam formations on a container to be closed, and a plasticsouter closure member shrouding the inner closure member and having acrown' to overlie at least part of the crown of the inner closure memberand a skirt to overlie the first said skirt, the outer closure memberbeing captive on the inner closure member and being at least in partaxially moveable on the inner closure member and biassed to a positionin which the outer closure member is freely rotatable on the innerclosure member in the sense todisengage the closure from the saidcontainer, there being provided means on the inner and outer closuremembers which are mutually engageable on depression of the outer closuremember or the said part thereof against the bias to provide a positivedrive between the closure members enabling disengagement of the closurefrom the container, a plurality of projections formed on the outerperiphery of the inner closure member skirt and a plurality of ratchetsin the form of thin tongues of plastics material which projectintegrally and inwardly from the outer closure member skirt intoengagement with the inner closure member skirt and which are engageablebehind the said projections so as at all times to enable a positivedrive to be effected between the members, in the sense to engage theclosure on the container and irrespective of the axial position of theouter closure member on the inner closure member, each ratchet beingarranged so as to ride resiliently over the said projections when theouter closure member is turned in the sense to disengage the closurefrom the container.

2. A closure according to claim 1, wherein the plastics material of theouter closure skirt is locally reduced in thickness adjacent the root ofeach ratchet, along at least one side of the ratchet.

3. A closure according to claim 1, wherein each ratchet comprises adeformable and resilient root portion, and a substantially rigid furtherportion to engage the skirt of the inner closure.

4. A closure according to claim 1 wherein the crown of the outer closuremember has a rigid cylindrical boss depending therefrom to engage thecrown of the inner closure member at its free edge, a portion of theouter closure member crown radially outside the boss being resilient anddeformable to allow the said axial movement of the outer closure memberon the inner closure member.

5. A closure according to claim 1, wherein the crown of the outerclosure member is formed with a well having a closed bottom to engagethe crown of the inner closure member, a portion of the outer closuremember crown radially outside the well being resilient and deshort lugsformed at intervals around the inside periphery of the skirt of theouter closure member, the lugs b'eing engageable between the knurls bythe said axial movement of the outer closure member on the inner closuremember.

1. A childproof closure, comprising an inner closure member having acrown and a depending skirt with cam formations for cooperation withcomplementary cam formations on a container to be closed, and a plasticsouter closure member shrouding the inner closure member and having acrown to overlie at least part of the crown of the inner closure memberand a skirt to overlie the first said skirt, the outer closure memberbeing captive on the inner closure member and being at least in partaxially moveable on the inner closure member and biassed to a positionin which the outer closure member is freely rotatable on the innerclosure member in the sense to disengage the closure from the saidcontainer, there being provided means on the inner and outer closuremembers which are mutually engageable on deprEssion of the outer closuremember or the said part thereof against the bias to provide a positivedrive between the closure members enabling disengagement of the closurefrom the container, a plurality of projections formed on the outerperiphery of the inner closure member skirt and a plurality of ratchetsin the form of thin tongues of plastics material which projectintegrally and inwardly from the outer closure member skirt intoengagement with the inner closure member skirt and which are engageablebehind the said projections so as at all times to enable a positivedrive to be effected between the members, in the sense to engage theclosure on the container and irrespective of the axial position of theouter closure member on the inner closure member, each ratchet beingarranged so as to ride resiliently over the said projections when theouter closure member is turned in the sense to disengage the closurefrom the container.
 2. A closure according to claim 1, wherein theplastics material of the outer closure skirt is locally reduced inthickness adjacent the root of each ratchet, along at least one side ofthe ratchet.
 3. A closure according to claim 1, wherein each ratchetcomprises a deformable and resilient root portion, and a substantiallyrigid further portion to engage the skirt of the inner closure.
 4. Aclosure according to claim 1 wherein the crown of the outer closuremember has a rigid cylindrical boss depending therefrom to engage thecrown of the inner closure member at its free edge, a portion of theouter closure member crown radially outside the boss being resilient anddeformable to allow the said axial movement of the outer closure memberon the inner closure member.
 5. A closure according to claim 1, whereinthe crown of the outer closure member is formed with a well having aclosed bottom to engage the crown of the inner closure member, a portionof the outer closure member crown radially outside the well beingresilient and deformable to allow the said axial movement of the outerclosure member on the inner closure member.
 6. A closure according toclaim 1, wherein the said means on the inner and outer closure memberscomprises knurls formed at intervals around the outside periphery of theskirt of the inner closure member, and short lugs formed at intervalsaround the inside periphery of the skirt of the outer closure member,the lugs being engageable between the knurls by the said axial movementof the outer closure member on the inner closure member.